package NowCoder.UnderlyingPrinciple;

public class 单选_7_5_18 {
    public static void main(String[] args) {
        StringBuffer sb1 = new StringBuffer("A");
        StringBuffer sb2 = new StringBuffer("B");
        add(sb1,sb2);
        System.out.println(sb1 +  " " +sb2);
    }
    public static void add(StringBuffer sb1 ,StringBuffer sb2){
        sb1.append(sb2);
        sb2 = sb1;
    }
}
